Temperature controlling system for electrical apparatus



Ap 1940- E. E. MOYER 2,196,022

TEMPERATURE CONTROLLING SYSTEM FOR ELECTRICAL APPARATUS Filed Nov. 27, 1956 2 Sheets-Sheet l Inventor": Elmo E. Moyer,

is Attorney.

A April 2, 1940.

E; E.' MOYER 2,196,022

TEIPERATURE CONTROLLING SYSTEM FOR ELECTRICAL APPARATUS Filed Nov; 27, 1936 2 Sheets-Sheet 2 454 47 M60 4! 49' u b CYJWLH is Attorney.

by H

Patented Apr. 2, 1940 UNITED STATES PATENT OFFICE TEMPERATURE CONTROLLING SYSTEM FOR ELECTRICAL APPARATUS Elmo E. Moyer, Scotia, N. Y., assignor to GeneYral Electric Company, a corporation of New ork Application November 27, 1936, Serial No. 112,905

3 Claims. (01. 250-27) My invention relates to control systems for elecand a control circuit for controlling the energizatrical apparatus and more particularly to temtion of the motor so that the system is initiated perature controlling systems for electron disin its operation when theload current exceeds a charge devices. predetermined value and maintained in opera- Heretofore there have been devised numerous tion for a predetermined interval after the load 5 arrangements for controlling the temperature current has attained a predetermined value. of electrical apparatus. Many of these prior art In accordance with another illustrated embodiarrangements have operated to cool the elecment of my invention, I provide a cooling system trical apparatus by circulating a cooling medium, for electrical apparatus in which the electrical m such as air, about the apparatus. In some inapparatus or an associated circuit or circuits are stances the cooling medium has been circulated controlled in the event the cooling system fails continuously about the apparatus, and in other to function in a predetermined manner. More of the prior art arrangements the cooling medium specifically, I provide a system for circulating has been controlled and circulated in accordance a cooling fluid about electrical apparatus and with the temperature of the apparatus. These which reduces the load imposed upon the elec- 15 prior art cooling systems have not been entirely trical apparatus in the event the cooling system satisfactory where the electrical apparatus is emfails to respond by supplying a suificient amount ployed in a system where the energy transmitted of cooling fluid. to the electric valve means within varies within wide limits and where it is dea predetermined time after the initiation of the sirable to anticipate a rise in temperature of the cooling operation. 2

apparatus so that the cooling system may be For a better understanding of my invention, placed in operation prior to a rise in temperareference may be had to the following descripture. For example, in circuits including electron tion taken in connection with the accompanying discharge devices, such as electric valve means drawings, and its scope will be pointed out in employing ionizable mediums, it is frequently the appended claims. Figs. 1 and 2 of the ac- 25 desirable to anticipate a rise in temperature of companying drawings diagrammatically show the electric valve means so that the cooling embodiments of my invention as applied to an system may be started prior to the actual rise in electric valve means for transmitting energy betemperature. tween an alternating current circuit and a direct It is an object of my invention to provide a new current circuit. 30

and improved cooling system for electrical appa- Referring to Fig. 1 of the accompanying drawratus. ings, I have chosen to show my invention as It is another object of my invention to proapplied to a cooling system for controlling the vide a new and improved temperature controlling temperature of electrical apparatus arranged for system for electron discharge devices. transmitting energy between an alternating cur- 35 It s a further Object of y invention to D rent circuit and a direct current circuit. An V de a w and improved Cooling System electric valve means I, preferably of the type electric valve means of the type employing ionemploying an ionizable medium Such as a, gas izable medmms gases or Vaporsor a vapor and having anodes 2 and 3, control In aqcordance with an mustratqd embodiment members 4 and 5 and a cathode B, is interposed 40 of my Invention I provide coohng system for between an alternating current circuit I and a controlling the temperature of electrif Yalve direct current circuit 8 to transmit energy theremeans wherein the cooling system is initiated b t A t f r e g 1 int r sad b in its operation to anticipate a rise in temperae Ween m r po 6 ture of the device in accordance with an elec tween the alternating current circuit 1 and the trical condition of the electric valve means, or electnc Valve means and the terminals f a in accordance with an electrical condition of secondary Winding thereof are Connect to anodes 2 and 3 of electric valve means I. Any

an associated circuit. Additional means, such suitable starting arrangement, such as a battery as temperature responsive means, are also associated with the electric valve means to main- H and a SWltCh may be associated with the tain the cooling system in operation so long as the mercury p Cathode 6 of electric ValVe means temperature of the electric valve means exceeds I to start the electric valve means I. Control apredetermined value. The cooling system commembers 4 and 5 may be energized from the prises a motor driven fan for circulating air alternating current circuit 1 through a convenaround the envelope of the electric valve means, tional excitation circuit including a transformer Call 53 and any conventional phase shifting arrangement such the rotary phase shifter i In order to control the temperature of the electric valve means i, I provide a cooling system for circulating a cooling medium or fluid, such as air, about the envelope of the electric valve means i. This cooling system may comprise a compartment housing 55, which is shown in partial crosssection and which substantially surrounds the envelope of the electric valve means I and in- IS. The fan it may be driven by a able electric motor ll which is directly con- 1:: Led to the fan It. The fan [6 draws air rough on intaire opening (not shown) and envelope of the electric valve means i and caps s the air through the opening it at the bottom of the compartment 55. Although for the purpose of explaining my invention I have to represent the cooling system as comprlr'ig a motor driven fan of the structure dia rammatically shown, it should be understood that in invention in its broader aspests may be applied to cooling systems generally wherein other structures and other cooling mediums and actuatele. .nts are employed.

To control the energization of the electric motor i? in accordance with an electrical condition of one of the associated circuits, such as the current transmitted by the electric valve means I or the current of the load circuit 8, I provide a control circuit [9 comprising a source of alternating current 20 and a current responsive device, such as a relay 2|, which is connected to be controlled in accordance with the current in the direct current load circuit 8. The alternating current circuit 20 may be connected to the alternating current circuit 1 and in the particular arrangement shown is utilized as the source of energy for the electric motor H. The current responsive relay 2! is designed to raise an armature member 22 without appreciable time lag and to open contacts 23 and 24 when the current of direct current load circuit 8 increases to a predetermined value. The control circuit l9 also includes a time delay relay or control device 25 having an armature member 25, an actuating coil 21, a movable contact member 28 and stationary contacts 29. The time delay relay 25 is designed to close the contacts 29 through the movable contact 28 without substantial time lag after the actuating coil 21 has been deenergized, and it is also designed to open the contacts 28 with a predetermined time delay established by a suitable means, such as a dashpot 35. or a self-synchronous motor, which the particular embodiment diagrammatically shown is attached to the armature 26. The actuating coil of the time delay device 25 is energized from the alternating current circuit 20 through an auto-transformer 3| which is employed to impress on the actuating winding 2'! a suitable voltage for which it may be designed. When the contacts of the time delay device 25 are in the closed circuit position. the electric motor ll is connected to be energized from the alternating current circuit 20 through conductors and 33.

In order to assiu'e that the cooling system is maintained in operation so long as the temperature of the electric valve means I exceeds a predetermined value, I employ a suitable temperature responsive device, such as a bimetallic thermostatic relay 34, which may be situated within the compartment [5 and adjacent to or in the proximity of the envelope of the electric valve means I to maintain the electric motor ll energized irrespective of the position of the time delay relay 25. The thermostatic relay 34 is connected through conductors 35 and 36 to energize the electric motor I! from the alternating current circuit 20 when a predetermined temperature of electric valve means is exceeded.

The operation of the embodiment of my invention diagrammatically shown in Fig. l of the accompanying drawings will be described when the electric valve means I is operating as a rectiher to transmit energy from the alternating current circuit 1 to the direct current load circuit 8. Let it be assumed that the rotary phase shifter I4 is adjusted so that suitable potentials are impressed on the control members 4 and 5 of electric valve means I, in order that the electric valve means I impresses on the direct current circuit 8 a voltage of a suitable magnitude. If the nature of the load circuit connected to the circuit 8 is such that the current experiences intermittent increases in value, it is desirable to initiate the operation of the cooling system to maintain the temperature of the electric valve means I within certain predetermined limits. When the current in the direct current circuit 8 increases to the value for which the current responsive device 21 has been adjusted, the armature member 22 will be raised to effect deenergization of the auto-transformer 3|, effecting thereby deenergization of the actuating winding 2! of the time delay device 25. As a re sult thereof, the armature member 26 will drop immediately, causing the movable contact 28 to bridge the stationary contacts 29. Motor I! will be energized through a circuit including circuit 20, stationary contacts 29 and movable contact 28 of the time delay device 25 and conductors 33 and 32.

So long as the current in the direct current circuit 8 exceeds the predetermined value for which the relay 2| is adjusted, the armature 22 thereof will be raised to open contacts 23 and 24. Under these conditions, the actuating coil 21 of the time delay relay 25 will be deenergized so that the motor II will be energized so long as the current in the direct current circuit 8 exceeds the predetermined value. When the current in the direct current circuit 8 decreases to a value less than the predetermined value, I

armature 22 of the relay 2| will drop to close contacts 23 and 24 to initiate a timing operation, interval of which is established by the time delay device 25. During this interval the motor will be energized to maintain the cooling system in operation a predetermined time after the load current has decreased below the predetermined. value. In this manner the system operates to cool the electric valve means I after the heavy load period of operation.

It is to be understood that the control circuit 19 will initiate operation of the cooling system to anticipate a rise in temperature of the electric valve means I in accordance with an increase in current in the circuit 8, so that the cooling system is maintained in operation for the duration of the large current condition and for a predetermined time after the current in the circuit 8 has decreased to a value less than the predetermined value. So long as the load current remains below this value, the cooling system is not placed in operation. In the event the temperature of the electric valve means I exceeds a predetermined value established by the setting of the thermostatic relay 34, the relay 34 will eflect energization of the electric motor I I from the alternating current circuit 20 so that the electric valve means I is cooled irrespective of the operation of the control circuit I9. When the thermostatic relay 34 moves to the closed circuit position, it will be noted that the electric motor I! is energized from the alternating current circuit 20 through conductors 32, 35 and 36. In this way, the thermostatic relay renders ineffective the control circuit I9 when the temperature of the electric valve means I exceeds a predetermined value.

Another embodiment of my invention is diagrammatically shown by Fig. 2. The electric translating system of Fig. 2 is substantially the same as that of Fig. 1 and corresponding elements have been assigned like reference numerals. As a means for controlling one of the associated circuits, for example the load circuit 8, in accordance with the operation of the cooling system, I have provided a pressure responsive device 31 which operates in accordance with the pressure of the air supplied by the fan I6. The pressure responsive device 31 includes a vane 38 which is placed within the housing or duct I5 and includes a movable contact member 39 and sta tionary contacts 40 and H. The movable contact member 39 is spring biased to engage the stationary contact 46 when the pressure of the air does not attain a predetermined value. When the pressure of the air attains or exceeds a predetermined value, the movable contact member 39 is brought into engagement with the stationary contact 4|.

A three phase alternating current circuit 42 is provided to energize the alternating current motor I1 and includes phase conductors 43, 44 and 45. As a means for initiating the operation of the cooling system by the energization of the motor I1 in accordance with an electrical condition of the electric valve means I or one of the associated circuits, such as the current of the direct current circuit 8, I employ a current :7 responsive relay 46 having movable contacts 4! and 48 and stationary contacts 49 and 49'. The current responsive relay 46 is of the type arranged to close substantially coincidentally with the occurrence of a predetermined current in the direct current circuit 8 and to remain closed so long as that electrical condition continues. Due to the time delay feature of the current responsive device 46, this relay effects energization of the motor IT for a predetermined interval of time after the occurrence of the electrical condition. It will be noted that the phase conductor 44 of the alternating current-circuit 42 is permanently connected to one terminal of the alternating current motor I1 and that the control of the motor I1 is effected by controlling the connection of phase conductors 43 and to the other two terminals of the alternating current motor II. As a means for providing a timing interval prior to the time the pressure responsive device 31 is made efi'ective. I employ a suitable timing device, such as a relay 50, having an actuating coil 5| connected to be energized from one phase of the alternating current circuit 42 and having a movable contact member 52 and stationary contacts 53. Relay 50 is designed so that the movable contact member 52 disengages stationary contacts 53 a predetermined interval of time after the closing of the current responsive device 46.

A normally closed thermostatic relay 54 is associated with theelectric valve means I and is tacts 65 and 66.

connected to the cathode 6 of electric valve means I through a conductor 55 and is connected to a circuit controlling means 56 through a conductor 51. A circuit controlling means 56 is provided with an actuating coil 58 which normally maintains this element in the closed circuit position. The actuating coil 58 is connected through a conductor 59 to the operating contacts 52 and 53 of the time delay relay 50 and the operating contacts of the time delay relay 50 are connected to the secondary Winding ID of transformer 9 through a conductor 60. A relay BI is employed to assure the continuous energization of the actuating coil 58 of the circuit controlling means 56 after the pressure of the air of the cooling system attains a predetermined value. The relay 6! is provided with an actuating coil 62, movable contact members 63 and 64, and stationary con- The actuating coil 62 is connected to be energized in accordance with the voltage appearing between phase conductors 43 and 44 through the pressure responsive device 31 when the movable contact member 39 is in the right-hand position and when this member engages the stationary contact 4|. This circuit includes a resistance 61, conductor 68, actuating coil 62, a conductor 69, which is connected to the movable contact member 39 of the pressure responsive device 31, stationary contacts 65 and movable contact member 63, and a conductor III. The contacts 65 and 63 of the relay 6| serve to assure the energization of the actuating coil 62 after the movable contact member 39 of the pressure responsive device 31 has been moved to the right-hand position and has initiated the actuation of relay 6|. Stationary contacts 66 and movable contact member 64 of relay BI provide a shunt path around the contacts of the time delay relay 50 so that the energization of the actuating coil 58 of the circuit controlling means 56 is assured after the pressure of the cooling air attains a predetermined value.

To provide a means for maintaining the cooling system in operation after the current responsive device 46 moves to the open circuit position in the event the temperature of the electric valve means I exceeds a predetermined value, I employ any suitable arrangement such as a thermostatic relay II of the snap acting type having stationary contacts I2 and I3, a permanent magnet I3, and a bi-metallic movable contact member I4. The movable contact member I4 is arranged to engage stationary contact I2 so long as the temperature of the electric valve means I remains below a predetermined value. When the temperature of the electric valve means exceeds this value, the movable contact member I4 rapidly moves to engage the stationary contact I3. A contactor I5 includes an actuating coil 15' which is energized in accordance with the voltage appearing across one phase of the alternating current circuit 42 and is controlled by the thermostatic relay 1!. When the movable contact member I4 of relay II engages the stationary contact I2 the actuating coil I5 of the contactor I5 is short circuited. However, when the movable contact member I4 engages the stationary contact I3, the actuating coil I5 of the contactor I5 is energized in accordance with the voltage appearing between phase conductors 43 and 44 of alternating current circuit 42 through a circuit including a resistance I6 and a conductor II. A conductor I8 is connected between stationary contact I2 and the common juncture of the resistance I6 and the actuating coil 15 of contactor 15. The thermostatic relay it serves to complete a shunt path around contacts 49 of the current responsive device 46 when the temperature of the electric valve means 1 exceeds a predetermined value. This shunt path includes a conductor 79 which is connected between stationary contacts !3 of thermostatic relay H and one of the contacts 49 of current responsive device 46 and a conductor 80 which is connected between movable contact member 14 of relay H and the other contact 49 of current responsive device 46.

The general principles of operation of the embodiment of my invention diagrammatically shown in Fig. 2 may be best explained by considering the electric translating system when energy is being transmitted from the alternating current circuit 1 to the direct current load circuit 8 through the electric valve means I. When the value of the current transmitted to the circuit 8 exceeds a predetermined value for which the current responsive device 45 has been adjusted, the current responsive device 46 will operate substantially instantaneously to cause movable contact members 47 and 48 to engage stationary contacts 43 and 48' respectively. The alternating current motor H will then be connected to phase conductors 43, 44 and 45 of the alternating current circuit 42 so that the cooling operation is initiated. So long as the current of the load circuit 8 exceeds the predetermined value, the current responsive device 46 will be maintained in the closed circuit position and the current responsive device 48 will open with a predetermined time delay after the current has decreased below the predetermined value, providing thereby an interval of cooling for the electric valve means I after the load current has decreased. So long as the temperature of the electric valve means I remains below a suitable value for which the thermostatic means H has been adjusted, the actuating coil 15' of the contactor '55 will be short circuited to prevent the closing of this contactor. However, if the temperature of the electric valve means I exceeds the predetermined value for which the thermostatic relay H has been adjusted, the movable contact member '54 will snap to the left-hand position to engage stationary contact 73 to provide a shunt path, including conductors 79 and 8%, around stationary contacts 49 of the current responsive relay 46, and to remove the short circuit from the actuating coil 15 oi contactor T5 to permit the contactor 75 to close. In this way, the alternating current motor 11 will be energized from the alternating current circuit 42 irrespective of the operation of the current responsive device 45 so long as the temperature of the electric valve means I remains above the predetermined value. When the temperature of the electric valve means dccreases, the movable contact member 14 will snap to the right-hand position, opening the shunt circuit around stationary contacts 49 and effecting short circuit of the actuating coil 15' of contactor i5 so that the motor H is deenergized.

Considering the system immediately after the closing of the current responsive device 46 in response to a load condition, it will be understood that the motor I! will be energized, and if the system is operating normally the cooling air will be circulated about the electric valve means I and will exert a pressure on the vane 38 of the pressure responsive device 31 so that the movable contact member 39 is brought into engagement with the stationary contact 4|. Immediately after the current responsive device 46 closes phase conductors 43 and 45, a timing operation is initiated by the energization of actuating coil 5| of time delay relay 5!). By virtue of this timing operation, there is provided an interval of time to permit the motor IT to accelerate to establish a pressure within the housing 15. During the period of the starting operation prior to the movement of the vane 38, the actuating coil 58 of the circuit controlling means 56 will be supplied direct current through a circuit including cathode 6 of electric valve means i, conductor 55, thermostatic element 54, actuating coil 58, conductor 58, contacts 52 and 53 of time delay relay 50, conductor 80, and secondary winding ii! of transformer 9. If the fluid pressure does not attain a predetermined value within the interval of time established by the time delay relay 53, this circuit will be interrupted by movement of movable contact member 52 to effect disengagement of this member relative to the stationary contacts 53, so that the above described energizing circuit for the actuating coil 48 will be interrupted. In this way the load circuit 8 is controlled if the cooling system does not function properly. However, if the fluid pressure attains a predetermined value to efiect movement of the vane 38 that the movable contact member 39 of the pressure responsive device 31 engages stationary contact 4i prior to the opening of contacts 52 and actuating coil 62 of relay 6! will be energized from the alternating current circuit 42 to provide a shunt path aroimd the contacts of time delay relay 5%, eiiecting continuous energization of the actuating coil 58 of the circuit controlling means 56. Prior to the movement of the vane 38, actuating coil 62 of relay 5! is short circuited through a circuit includin conductors 68 and 59 and contacts 39 and 49 of the pressure responsive device 31. When the actuating coil 62 of relay Si is energized, causing movable contact 63 to bridge stationary contacts 65, a shunt path is established around movable contact and stationary contact 4| of the pressure responsive device 3'! so that the effect of chattering, due to fluid pressure variations, is eliminated. In this manner, it will be understood that I provide an arrangement for controlling the load circuit 8 or for protecting the electric valve means I from excessively high temperatures in the event the cooling system fails to operate in a satisfactory manner. As an additional protective feature, the thermostatic relay 54 will operate to disconnect the load circuit 8 by the deenergization of coil 58 of the circuit controlling means 56 in the event the temperature of the electric valve means i exceeds a safe operating value.

While I have shown and described my invention as applied to a particular system of connections and as embodying various devices diagramcw matically shown, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination, an electric circuit, electric apparatus connected thereto, a cooling means for circulating a cooling fluid about apparatus, means for initiating the operation of said first mentioned means in accordance with an electrical condition of said apparatus, and means for controlling said circuit in the event the F pressure of said fluid does not attain a predetermined value within a predetermined time after the initiation of the operation of said cooling means.

2. In combination, a supply circuit, a load circuit, translating apparatus interposed between said circuits for transmitting energy therebetween, a cooling means for circulating a cooling fluid about said translating apparatus comprising a fan and an alternating current driving motor therefor, an alternating current circuit for energizing said motor, means responsive to an electrical condition of said load circuit for connecting said motor to said alternating current circuit, means for controlling said motor in accordance with the temperature of said translating apparatus, and means for disconnecting said load circuit in the event the pressure of said fluid does not attain a predetermined value within a predetermined interval of time after the initiation of the operation of said cooling means.

3. In combination, an electric circuit, electric translating apparatus connected to said circuit, cooling means for circulating a cooling fluid about said translating apparatus comprising a fan and a three phase alternating current driving motor therefor, a three phase alternating current circuit for energizing said motor and having one phase conductor permanently connected to said motor, means for energizing said motor in accordance with an electrical condition of said apparatus including a device for connecting the other two phase conductors of said three phase alternating current circuit to said motor, and means for controlling said motor in accordance with the temperature of said apparatus after the initiation of the operation of said motor by said device including a thermostatic element for completing the energization of said motor through said other two phase conductors so long as the temperature of said apparatus remains above a predetermined value and for effecting deenergization of said motor by disconnecting said other phase conductors of said alternating current circuit from said motor when the temperature of said apparatus is less than a predetermined value.

ELMO E. MOYER. 

